Probability-based static truck loading model for rural bridges in Saskatchewan

Abstract

A study was conducted to establish a new truck load model intended for the evaluation and design of bridges with simple spans of 20 m or less located on rural roads in Saskatchewan. Monte Carlo simulation was used to generate truck data sets based on site-specific traffic conditions determined from a traffic count program conducted between 2008 and 2012 across all 296 rural municipalities, and data collected from six weigh-in-motion stations in the province from January to December 2013. All axle weights and spacings were modelled as probabilistic parameters. The critical truck configuration featured a truck tractor with a steering axle and tandem axle group, and a truck trailer with a tridem axle group. Truck models with a common axle configuration but varying weights were developed for various reference periods that reliably reproduced extreme nominal load effects over those periods. The use of other data sets may lead to different results.